A method and a computer program product that enable an existing operating system (OS) to provide a non-failure response to an application's reference to an OS service that is not currently defined/available within the existing OS. The loader of the OS responds to each reference to an undefined service by mapping the reference to an undefined service response utility (USRU). USRU is a specialized service designed to provide a response that a requested service is not yet available. When the OS loader detects that an application is referring to an OS service that is undefined, the OS loader resolves the reference to the USRU, which, when invoked returns an indication that the requested service is not yet available.